Metal-enriched Pair-instability supernovae: Effects of rotation

Abstract

In this paper we revisit metal-enriched rotating pair instability supernovae (PISNe) models for metallicities consistent with the Small Magellanic Cloud (SMC), the Large Magellanic Cloud (LMC) and 0.1$Z_\odot$. By calculating multiple models, we intend to clarify mass ranges and the ejected $^{56}$Ni masses from the PISNe, and mass loss histories for progenitors. We find the choice of the Wolf-Rayet (WR) mass-loss rates are important and we adopt the recently proposed rate of Sander & Vink (2020), which covers the mass ranges for PISNe progenitors. We show that slow rotation lowers the PISN range due to the increase in core mass by rotational mixing. On the other hand, if we assume typical rotation speed for observed OB stars, the mass loss increase becomes more significant and the final stellar masses are smaller than non-rotating models. As a result, typical mass range for bright SNe, with $^{56}$Ni mass more than 10${ M}_\odot$ for such fast rotating models are more than 400, 350 ${ M}_\odot$, for LMC and 0.1$Z_\odot$ metallicities, respectively. It is interesting that, unlike previous works, we find Oxygen rich progenitors for most cases. This O-rich progenitor may be consistent with the recently identified PISN candidate SN2018ibb. He-rich progenitors are seen only for relatively dim and metal poor ($Z \lesssim 0.1 Z_\odot$) PISNe. We also discuss the black hole mass gap for metal-enriched PISNe, and show that the upperbound for the gap is lower than in the Pop III case.